Case. One partner has a chronic illness; roles shifted to “patient and caregiver”, and “the two of us” dissolved.
Model. A long background load reshaped the roles; without maintenance the “couple” loop degrades.
Protocol. Explicitly protect the relationship beyond the care roles; accept outside help; don’t let the illness become the only topic.
Lesson. Illness changes the load but need not erase the couple.
See High availability.